U.S. Pat. No. 6,468,053 describes a blower having a housing wherein an internal combustion engine is mounted. The internal combustion engine drives a blower wheel, which generates a stream of air in a blower pipe.
Generally, blowers are not equipped with couplings. Accordingly, when the internal combustion engine is running at idle, the blower wheel continues to be powered. Consequently, there is also a stream of air in the blower pipe when the engine is at idle, and this, in turn, can raise dust and dirt. The output during idle operation is also relatively high, which results in high fuel consumption during idle.